Journals of Gerontology Series B: Psychological Sciences and Social Sciences, Vol 51, Issue 6 P346-P355, Copyright © 1996 by The Gerontological Society of America
Aging and motor control
S Chaput and L Proteau
Departement d'education physique, Universite de Montreal.
The goal of the two experiments of the present study was to determine
whether in an aiming task performed within a relatively long movement time
(MT) bandwidth, older adults make similar use of visual information for
motor control as younger adults. Older and younger subjects practiced a
manual aiming task toward one (Experiment 1), or one of many (Experiment 2)
small target(s) while only the target to be reached was visible
(proprioception only: P) or under normal lighting condition
(proprioception+vision: PV). Following practice, all subjects were
transferred to the P conditions. The results of both experiments indicate
that the older subjects were, during practice, as accurate as the younger
ones in the PV condition. Moreover, both groups suffered a large and
similar increase in aiming error in the transfer condition. This underlines
that a useful source of sensory information, namely vision, has been
withdrawn in transfer. This result is different from those of earlier
studies in which a shorter target MT had been used (Chaput & Proteau,
1996; Proteau, Charest, & Chaput, 1994). This suggests that older
adults process the sensory information available in that type of task
similarly to younger subjects but at a lower speed. However, when the
temporal constraints of the task are stringent, older adults might rely
more on modes of control in which sensory information plays a minimal role
when compared to younger subjects. Finally, the results of the second
experiment suggest that, when multiple targets are used, older adults
appear to program a response which is optimally suited for a "central"
target.
